Refrigeration



May 19, 1931- J. G. BERGDOLI. 1,805,901

v @Mygdm May 19, 1931. J. G. BERGDOLL REFRIGERATION Filed Nov. 19. 19292. Sheets-Sheet 2 gwuenkw Patented May 19, 1931 UNITED STATES PATENToFFicE IOHN G. BERGDOLI, 0F YORK, PENNSYLVANIA, ASSIGNOR TO YORK ICEMACHINERY CORPORATION, OF YORK, PENNSYLVANIA, A CORPORATION OF DELAWAREREFRIGERATION Application led November 19, 1929. Serial No. 408,363.

This invention relates to refrigeration, and particularly to means forcontrolling the feed of liquid refrigerant to flooded evaporators.

The usual control involves a float valve, lo-

cated at the level which it is desired to maintain in the evaporator. Assuch evaporators are in many cases submerged in brine tanks, the floatvalves are commonly not readily accessible for inspection and repair.

The present invention overcomes this maintenance dilculity, by providingan arrangement in which the valve and float may be located above theliquid level in the evaporator.

Generally stated, the float responds to the rise and fall of a column ofliquid (preferably refrigerant) which balances a liquid clumn in theevaporator, the two columns being connected by a pressure transmittinglink p1 of refrigerant vapjor.

A preferred em odiment of the invention is illustrated in theaccompanying drawings, in which,

Fig. 1 isan end elevation of an evaporator with. the invention applied.

Fig. 2 is a fragmentary side elevation of the same.

Fig. 3 is an enlarged vertical section through the float valve.

Fig. 4 is a section on the line 4-4 of Fig. 3.

An evaporator of the type described and claimed in the patent toShipley, No. 1,718,313, is illustrated, but any flooded evaporator orsimilar closed volume in which a maintained might be substituted.

The vertical drum 6 serves as a receiver suction trap. The lower orliquid headers of the evaporator appear at 7, and the Aupper or asheaders at 8. These are substantially horizontal and are connected byV-shaped riser tubes 9. The liquid level in the evaporator is indicatedby the line A-A, and is approximately at the centers of the upperheaders 8.

Connected at the upper end of the drum 6 is the suction line 11, whichleads to the compressor, not shown.

The liquid supply line 12 is connected to deliver liquid to the drum 6either through 5 afloat controlled valve (normal operation) or definitelevel of liquid refrigerant is to be 21.V The rod 21 is pivoted atthrough an expansion valve, but before describing the connections, theconstruction and arrangement of the Boat controlled valve will beexplained.

The float valve mechanism includes a float chamber housing 13. From thetop of this there leads a pressure equalizing connection 14 to theinterior of drum 6 above the liquid level A-A. This connection iscontrolled by a normally open stop-valve 15. From the bottom of floatchamber housing 13 a pipe 16 leads to the interior of the drum 6 belowthe liquid level A-A, and preferably near the bottom of the drum. Aliquid seal trap 17 is interposed in pipe 16 and in practice this isconveniently formed as a simple loop. A normally open stop valve 18 isinterposed in The level of the liquid seal in trap 17 is here shown asycoincident with the line A-A, i. e., the level of liquid to bemaintained in the evaporator. The float Valve mechanism is arranged, ashereinafter described, to maintain a level .B-B in the chamber 13 sothat the pipe 16 down to the level A-A, at which the trap 17 functions,is filled with liquid refrigerant. Belowl the level A-A and down to thelevel C-C, which marks the upper limit of the connection between pipe 16and drum 6, the pipe 16 is filled with refrigerant vapor.

This follows from the fact that vapor evolved from liquid refrigerant inpipe 16 below trap 17 isv prevented from flowing upward by this trap.Hence it displaces liquid downward and into the drum 6, until the pipeis free of liquid.

This vapor serves as a substantially weightless pressure mediuminterposed between a liquid column H1 in drum 6 and the liquid column H2in pipe 16 and chamber 13. In the illustrated embodiment both columnsare of liquid refrigerant, so H1: 2.

Referring now particularly to Figs. 3 and 4, it will be observed that inthe chamber 13 there is a float 19 which is carried on a rod 22 on abracket provided for that purpose and carries an olfset arm or lug 23which is pivoted at 24 to a link 25. The link 25 is pivoted at 26 to abalanced piston slide valve 27. This valve has the usual sealing grooves28 and a port groove 29. It slides in a cylindrical seat bushing 31which is pressed into the housing member 32, which in turn is bolted tothe housing 13 forming the float chamber. A gasket 33 affords a tightseal.

The liquid refrigerant is supplied to a y chamber 34 by connectionsAhereinafter described, and thence iows to two opposed seat ports 35 inthe bushing 31. When the valve 27 is carried to the left by the descentof the float 19 (see Fig. 3), the groove port 29 connects the two ports35 with a pair of opposed ports 36 (see Fig. 4) which are spaced at 90to the ports 35 and lead obliquely to a' discharge channel 37. Thechannel 37 communlcates by a passage 38 with a discharge connection. Albranch passage 39 of small dimension bleeds off a limited portion ofliquid from the passage 38 and delivers it to the float chamber 13.

When the liquid level in the chamber 13 rises to the level B-B theresulting rise of the float 19 will move the valve 27 far enough to theright to carry the groove 29 out of register with the ports and 36, thuscutting oil' the flow of liquid refrigerant. The liquid line 12 isconnected through a stop 30 valve 41 and a strainer 42 with the supplychamber 34. The discharge passage 38 is connected by way of stop valve43 and pipe 44 to the interior of the drum 6, thepipe 44 dischargingbelow the liquid level A--A, as 35. clearly shown in the drawings.

The valves 41, 43, 15 and 18 are normally open, but in the event that itis desired to put the float control out of action and regulate thesupplyof liquid refrigerant by a hand operated expansion valve,` the valves41, 43, 15 and 18 are closed and the flow is regulated by an expansionvalve 45 which oifers a bypass between the pipes 12 and 44. AThisfeature is illustrated merely to explain the possi- 45 bility of makingsuch connection. Normally the valve 45 is closed and the feed iscpntrolled by the iioat valve mechanism.

The port 39 lhas an important function.-

The float chamber 13 is connected with the vapor space in drum 6 by thepressure e ual- Lizing pressure connection 14, and some re rigerantevaporatesfrom the chamber 13.` Under sustained load conditions valve 27seldom closes completely, so that a small quantity of |55 refrigerant isfed continuously or at frequent intervals by way of the passage 39 tothe float chamber. The passage 39 is so dimensioned that the quantity ofliquid so fed is at least equal to the maximum evaporative loss from 80the chamber 13. Any excess causes a slow flow of liquid refrigerant downthe pipe 16 and through the trap 17. This flow should be so limited asto avoid any tendency to ilood the gas-filled portion of the pipe 16below the trap 17.

= stant liquid level therein,

-so that the level A-A in the drum 6 coincides with the sealing level ofthe trap 17, this arrangement is not vitally essential and ma bedeparted from. The im ortant thing 1s that the liquid column H2 s. allbalance the liquid column H1. It is far simpler to use refrigerantliquid for both columns, but it is within the range of possibility touse a different liquid for the column H2. In such case the columns wouldbalance each other but would not necessarily be of the same height,

this being controlled by their relative specific gravities.

The operation of the device will be clean from the description alreadygiven.

In certain of the claims the portion of pipe 16, above the sealing levelof trap 17 together with the liquid filled portion of chamber 13, arereferred to as a l nometer for, in effect the column H2 is merely amanometer column. f

What is claimed is,- 1. The combination with an evaporator, of means formaintaining a substantially'con'.- stant liquid level therein,comprising a liquid containingmanometer a valve controlling thesupply-of liquid refrigerant to the evap-v orator; operating means forsaid rvalve reiquid containing masponsive to the height of the liquidin' said .y

manometer; a pressure transmitting connection between said manometer anda pointy within the evaporator below the liquidlevel therein, and meansfor developingin said connection a vapor pressure at least equal to thehead of the\ liquid refrigerant at said point. 'Y

2. The combination with an evaporator, of means for maintaining asubstantially constant liquid level therein, comprising a liquid jcontalnlng manometer; a valve controllingv the supply of liquidrefrigerant to the evapo. rator; operating means forsaid valveresponsive to the height of the liquid in said manometer; a pressureequalizing connection between the upper end of the manometer and the.vapor space above the liquid inthe evaporator; a pressure transmittingconnection between said manometer and a point within the evaporatorbelow the liquid level therein; and means for developing in saidconnection a vapor pressure at least equal to thehead of.

the liquid refrigerant at said point."

3. The combination with an evaporator, of means for maintaining asubstantially concomprising a ma-h \-\means for developing in saidconnection a a pressure 5 sald manometer and a nometer containing acolumn of liquid refrigerant; a valve controlling the supply of liquidrefrigerant to the evaporator; operating means for said valve responsiveto the height of the liquid column in said manometer; a pressuretransmitting connection between said manometer and a point within theevaporator below the liquid level therein; and

orator below the liquid level therein; and means for developing in saidconnection a refrigerant vapor pressure at least equal to the head ofthe liquid refrigerant at said point.

5. The combination with an evaporator,

of means fof maintaining a substantially constant'liquid levelthere1n,compris1ng a manometer containing a column of liquidrefrigerant; a valve controlling the supply of liquidrefrigerantto theevaporator; operating means for said valve responsive to the height ofthe liquid column in saidA manometer; a pressure equalizing connectionbetween the upper .end of the manometer and the vapor space above theliquid in the evaporator; a pressure transmitting connection betweensaid manometer and a point within the evaporator below the liquid leveltherein; means for developing in 'said connection a refrigerant vaporpressure at least equal' to the head of the liquldrefrigerantfjat saidpoint; and means for supplying liquid refrigerant to said manometercolumn at a restricted rate.

6. The combination with an evaporator, of means for maintaining asubstantially constant li uid level therein comprising a valvecontrolling the suppl -of liquid refr' erant to the evaporator; aA oatchamber andg a liquid sealed trap arranged to define a manometer column;a pressure equalizin connection from the iioat chamber tot e vapor spaceof the evaporator; a pressure transmitting connection between the trapand a point within the evaporator below the liquid level therein; and afloat in said ioat chamber connected to .close said valve upon a rise ofliquid level in said chamber.

oint within the evap- Y stant liquid level therein comprisin a valvecontrolling the supply of liquid re ngerant to the evaporator; a o uid,sealed trap arranged to dene a manomf eter column; a tion from thespace of theevaporator; a pressure transmitting connection between thetrap and a at chamber and a liqressure equalizng connecoat chamber tothe vapor point within the evaporator below the liquid Y level therein;a float in said float chamber connected to close said valve upon a riseoflliquid level in said chamber; and meansv for feeding liquidrefrigerant at a restricted rate to said chamber. l v

` 8. The combination with an evaporator, means for maintaining asubstantially constant liquid level therein, comprising a valvecontrolling the supplv of liquid refrigerant to the evaporator; a oatchamber and a liquid sealed trap arranged to define a manometer column;a ressure equalizingponnection from the, oat chamber to the vapor spaceof the evaporator; a pressure transmitting connection between the trapand a point within the evaporator below the liquid level therein; afloat in said float chamber connected to close said valve upon a rise ofliq-4 uid level in said chamber; vand means cpntrolled by said .valverefrigerant at a lrestricted rate to said chamber. v

-In testimony whereof I have signed my name to this specification. JOHNG. BERGDOLL.

7, The combination with an evaporator, of

means for maintaining a substantially confor feeding liquid

